By RICHARD FARR, SPECIAL TO THE POST-INTELLIGENCER

Updated 10:00 pm, Thursday, April 24, 2003

"Well, doctor, we want her to be tall, musically gifted and cancer-risk minimized. We'll take the Pleasant Personality Package, too."

Designer children are a science-fiction cliche, but Bill McKibben thinks they may be just around the corner. And in "Enough: Staying Human in an Engineered Age," he argues the "germ-line" genetic engineering needed to produce them is a Pandora's Box that humans must seal shut forever before it's too late.

In his best-known book, "The End of Nature," McKibben sounded the alarm about global warming. "Enough" continues that theme by examining two very scary things we may be about to do: irreversibly change the human genetic heritage and irreversibly unleash autonomous, uncontrollable nanotechnology.

With "genetech," the promise is people who are smarter, healthier and longer-lived -- even immortal, if you listen to the serious dreamers. With "nanotech," the promise is powerful micromachines that can clean oil spills, magically assemble food out of trash, even clean the insides of our own bodies.

Both dreams come with the same nightmare: the capacity for the technology itself, once used, to replicate indefinitely beyond our control.

But McKibben has two different arguments for fearing and regulating these technologies and the first half of his book is mainly about the more philosophical worry, which he never clearly states. Roughly, it's the idea that genetic engineering will render the lives of the "engineered" meaningless.

Granted, there's something creepy about rich parents getting into an arms race over the best IQ implants. And far creepier possibilities abound. (Let's have a kid who's a ruthless go-getter! Let's have a kid who glows in the dark!)

Still, McKibben's gut response, that these future people will feel robbed rather than gifted, is one he repeats rather than argues for. Maybe he's right. But the reasoning offered reduces to little more than romantic pessimism based on the idea -- radically mistaken, in this reviewer's opinion -- that even today we live less "meaningful" lives than our ancestors.

McKibben is on firmer ground -- and spends more time on the science -- when he describes how microscopic "nanoassemblers" could get out of control, the subject of Michael Crichton's recent best seller, "Prey." Imagine programming them to eat an oil spill. Great, unless a design flaw causes them to go after all environmental carbon instead. Then they would multiply like a virus until they had quite literally eaten the biosphere.

Even here, though, McKibben tends not to separate the musings of "technotopian" bubbleheads from the research of scientists. Sure, part of the chilling point is that even some Nobel Prize winners are as offensive or plain dimwitted about these issues as the "X-Files" crowd. Exhibit A: James Watson. Still, the reader is left in the dark about whether there are serious scientists who have thought honestly about McKibben's concerns.

Despite some accurate asides, there's also very little here to allay widespread public illusions about the science, such as that each gene is "for" some trait. As McKibben notes, a major result of the Human Genome project has been the discovery that we have only 30 percent as many genes as we thought and only twice as many as a fruit fly. What this implies is that we have even less idea than we thought about how our genes build something that can talk and not just buzz. Maybe we have a long way to go after all.

Having said this, there's no doubt McKibben has lit on an issue that needs debating. In a phone interview from his mountain home in New York state above Lake Champlain, he mentioned a germ of the book was recent science fiction:

"People who don't read science fiction think it's still all space exploration and how great the future will be. Look at an author like William Gibson, the Vancouver, B.C., writer whose most recent book is 'Pattern Recognition.' He writes appallingly bleak dystopias. Why? Partly because he has confronted the plausible consequences of our technology."

Can we stop the juggernaut, or slow it long enough to think straight? McKibben's examples of societies that have deliberately rejected a technology aren't encouraging: two are medieval China and Japan. The third is most interesting, and McKibben relishes dropping the rhetorical bomb that the most technologically sophisticated communities in America are Amish. (They don't have everything we have. What they do have is the ability to be ruled by considered judgments about which technologies to adopt.)

The cheerleaders aside, there isn't enough written on these issues, and, for all its flaws, "Enough" may provide a starting point for a vital debate. .

Or to put it another way: "We'd like her to be a brilliant scientist, but not hopelessly arrogant and immature about philosophical and social issues. Are those genes compatible, doctor?"